Intestinal Protozoa and Helminths in Asymptomatic Adults in the State of Zulia State, Venezuela

Prevalence studies for intestinal parasites are usually performed on children, since they are the most susceptible to these infections; however, this research was conducted to assess the situation in adults. Stool examination was performed on 95 asymptomatic persons over 18 years old, from three different locations in the state of Zulia, Venezuela. Fecal samples were submitted to microscopic examination with SSF-Lugol and the concentration method with formalin ether. Sixty-four individuals (67.36%) had one or more species of intestinal parasites and of these, 81.25% had at least one parasite pathogenic for humans. Thirty-one individuals had more than one parasite species (polyparasitism), with a maximum of three species per host. Seven intestinal protozoa species were identified, including pathogens and commensals, as well as 2 species of helminths. Protozoosis cases predominated (93) over helminths (10). The greatest frequencies corresponded to Blastocystis sp. among protozoa and Ascaris lumbricoides among helminths; also, there was a predominance of A. lumbricoides and Trichuris trichiura in the community Los Pescadores, when comparing the three communities studied. The most frequent parasitic association was Blastocystis sp. with several amoebas. This study found a high prevalence of intestinal protozoa and particularly Blastocystis sp.